Project scheduling cost optimization based on resource transfer costs and robustness

Under an uncertain environment, the reasonable arrangement of project scheduling and resource allocation can help managers save more on project costs. This paper focuses on the project scheduling cost optimization problem based on resource transfer costs and robustness under an uncertain environment. The optimization model of the problem is constructed with the objective to minimize the resource transfer costs and maximize the robustness. After accounting for the costs of transferring resource units across activities, we present a new project network graph consisting of unit resource flows. In addition, the robustness index is set based on the cost. To further ensure the robustness of the project, a time buffer insertion mechanism based on activity integrated delay penalty cost is designed. Then a developed non-dominated sorting genetic algorithm II (NSGA-II) is constructed to make the algorithm have better solving performance. The results of numerous experimental instances also serve as proof of the developed algorithm's effectiveness. Finally, we construct three uncertainty environments to further illustrate the performance of obtained solutions. The research results can provide a reference for project managers to make schedules and optimize project costs under uncertain environments.